The New World’s earliest known example of engineered water pressure was discovered by two Penn State archaeologists in the Maya city of Palenque, Mexico.

“Water pressure systems were previously thought to have entered the New World with the arrival of the Spanish,” the researchers wrote in a recent issue of the Journal of Archaeological Science. But this water feature predates the arrival of Europeans.

The city of Palenque was built around the year 100 in a constricted area with little land to build on and spread out to. By the time the city’s population hit its zenith during the Classic Maya period from 250-600, the Maya had saved precious urban space by routing streams beneath plazas using aqueductlike structures.

The pressurized water feature is called Piedras Bolas Aqueduct, a spring-fed channel on steep terrain.

From the tunnel’s entrance to its outlet 200 feet downhill, the elevation drops about 20 feet and its diameter decreases from 10 feet near the spring to about a half a foot where the water emerges.

This combination of a downhill flow and sudden channel restriction pressurized the water, shooting it from the opening to an estimated height of 20 feet.

The researchers don’t know for sure how the Maya used the pressurized water, but they have a couple of ideas.

One possibility is they used it to lift water into the nearby residential area for wastewater disposal. Another possibility, and the idea the researchers used as their model, was as a fountain.